Alert archive / Texas / Mesoscale Discussions in 2021

Mesoscale Discussion 881

June 8, 202115 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jun 8, 2021, 4:53 AM CDT for 15 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 8, 2021, 4:53 AM CDT (09:53 UTC)
Expired
Jun 8, 2021, 7:00 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%

Counties Bandera County, TX, Blanco County, TX, Burnet County, TX, Comal County, TX, Gillespie County, TX, Hays County, TX, Kendall County, TX, Kerr County, TX, Lampasas County, TX, Llano County, TX, Mason County, TX, McCulloch County, TX, Medina County, TX, Mills County, TX, San Saba County, TX

The radar

The Ft Hood radar (KGRK), 142 km from the middle of the area, began a volume at 09:53 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 9.9 hours before the alert went out and 249 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Fort Worth, TX at 00:00Z on 2021-06-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 488 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Worth, TX at 00:00Z on 2021-06-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 143 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
488 J/kg
Mixed-layer CIN
-212 J/kg
Mixed-layer LCL
1123 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
143 m²/s²
0-3 km storm-relative helicity
201 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

As transmitted.

923 
ACUS11 KWNS 080954
SWOMCD
SPC MCD 080953 
TXZ000-081200-

Mesoscale Discussion 0881
NWS Storm Prediction Center Norman OK
0453 AM CDT Tue Jun 08 2021

Areas affected...Parts of the Texas Edwards Plateau and Hill Country

Concerning...Severe potential...Watch unlikely 

Valid 080953Z - 081200Z

Probability of Watch Issuance...20 percent

SUMMARY...A gradually weakening cluster of storms may approach the
Austin and San Antonio areas by 8-9 AM, accompanied by strong
surface gusts perhaps at least approaching severe limits.

DISCUSSION...A relatively compact but fairly strong convectively
driven surface cold pool (with 2-4 mb 2 hourly surface pressure
rises and 50+ kt rear inflow within the lowest kilometer AGL) has
been maintained across and south/southeast of the Abilene vicinity,
with a forward propagation up to 40 kt.  While a modest and
gradually veering, south to southwesterly, low-level jet has been
focusing strongest renewed thunderstorm development on the
southern/southwestern flank of the cold pool, this forcing appears
likely to gradually weaken through daybreak.  However, given the
seasonably moist boundary layer, characterized by large CAPE on the
order of 2000-4000 J/kg, which extends far downstream, coupled with
the current strength of the cold pool, it is possible that
convection may be slow to weaken.  And it could approach the Austin
and Greater San Antonio areas by 13-14Z.

..Kerr/Edwards.. 06/08/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FWD...EWX...SJT...

LAT...LON   31609919 31609871 31709832 31569818 29739769 29279927
            30579956 31479938 31609919

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 7, 7:03 PM CDTMesoscale DiscussionSPCBailey, Borden, Castro, Cochran, Crosby, Dawson and 16 more2 hr
Jun 7, 9:04 PM CDTSevere Thunderstorm WatchSPCBriscoe, Castro, Childress, Cottle, Crosby, Dickens and 7 more5 hr
Jun 7, 10:28 PM CDTMesoscale DiscussionSPCBriscoe, Castro, Cottle, Crosby, Dickens, Floyd and 10 more92 min
Jun 8, 1:11 AM CDTMesoscale DiscussionSPCBaylor, Fisher, Haskell, Jones, Kent, King and 6 more2 hr
Jun 8, 10:11 AM CDTMesoscale DiscussionSPCCherokee, Gregg, Harrison, Marion, Panola, Rusk64 min

Nearby

Mesoscale Discussions in Texas, 2021Every mesoscale discussion in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.